1 New Nature: Overtoom Middelveen

Overtoom-Middelveen through the years
Overtoom-Middelveen through the years

1.1 Introduction


Location and Background

Overtoom–Middelveen is a newly developed nature reserve located between Rijssen and Holten in the province of Overijssel. The area covers approximately 150 hectares and connects surrounding nature areas such as De Borkeld, Elsenerveen, and the Sallandse Heuvelrug.

The area was formerly used for agriculture—mostly maize fields and pastures—but has recently been transformed into a rich wetland landscape.


Unique Ecological Features

One of the area’s most striking features is its groundwater seepage (kwelwater), which naturally brings water to the surface and creates shallow wetlands, also called “plas-dras” zones.

These moist conditions support a range of rare and protected plant species, including orchids, marsh gentians, grass-of-Parnassus, and saw sedge. Because of its ecological richness, Overtoom–Middelveen has been designated a core area for nature conservation.


Birdlife and Wildlife

More than 140 bird species have been observed in Overtoom–Middelveen, making it an important area for ornithology.

Key breeding and migratory species include lapwing, black-tailed godwit, redshank, and oystercatcher. In spring, birds such as curlew, bluethroat, reed bunting, and great reed warbler return from their winter habitats. Rarer birds like the corncrake and little crake are also seen regularly.

The area also supports mammals (such as hares and partridges), amphibians, dragonflies, butterflies, and a variety of insects.


1.2 Objective

The current state of your model does not contain the hydrological adjustments to preserve/improve the upward seepage coming from the Sallandse Heuvelrug

1.2.1 Research Questions

What is the effect of reducing the drainage system within the new nature area and in the direct surrounding of the nature with a maximal radius of 1500 from the centre of the nature reserve.

What is the effect of lowering the surface elevation of the new nature by 50 cm, removing the nutrients of the soil substantially

Does your model simulate the larger region around the Overtoom Middelveen in a reasonable way?

1.2.2 Approach

Calibrate your model

Reduce the drainage in and in the surrounding area and determine the effect on the upward seepage

Remove the upper soil of the new nature with 50 cm and determine the effect on the upward seepage.